Welding device



July 8, 1952 c. c. PEcK ETAL WELDING DEVICE 6 Sheets-Sheet l Filed March 3, 195o July 8, 1952 c. c. PEcK ET A1. 2,602,869

' WELDING DEVICE Filed Mauren 3, 195o e sheets-sheet 2 July 8, 1952,. n c. c. PEcK E'rAL 2,602,869

WELDING DEVICE IN V EN TOR ATTEFEXS.

July 8, 1952 c. c. PECK ETVAL WELDING DEVICE 6 Sheets-Sheet 4 Filed March 5, 1950 INVENTORS CEc/ c. Pack @No BY waa-A20 auA/zELMAAr July s, 1952 Filed March 3', 1950 l V /l/ /X/// C. C. PECK ET AL 6 Sheets-Shea?I 5 V///.//////////H,ef f g/ ////////////////f l r' \$i\\\ \\|l\\\\ 46 3e 48 3e 5,296 f L LI" LJ INVENToR C56@ c. Pam: an Yunnan ca/vzfl. MAN

Patented July 8, 1952 2,602,869 WELDING DEVICE Cecil C. Peck, Euclid, and Willard Giunzelman, Gates Mills, Ohio, assignors to Cecil C. Peck Company, East Cleveland, Ohio, a. Ycorporation yApplication:March 3, 1950, Serial No..147,'376

. 11 Claims.

This invention relates as indicated to Va novel welding device and method of welding andjmore particularly to Va device and 'method employing the electric rarc and a welding `'electrode to vjoin two metal members together.

The designing engineer has available :a variety of -methods and techniques .for joining metal parts` Thus, rivets have long been standard in the .fabrication of steel frame structures such as buildings and bridges. Electric arc welding is commonly employed to Ijoin abutting edges or steel plates, and .spot 'welding is .frequently used in the 11n-ass production of articles comprised of sheet metal stampings and the like. :Eachmethod has .its special advantages and deiiciencies. Consequently, situations vnot infrequently arise when -no one fof such commonly 'employed .methods is `suitable in achieving the desired physical characteristics at low cost and with sulicient rapidity to permit oi the employment of mass production techniques. One such situation arises, for example, when it is desired to secure a forged combine rasp bar to its channel-form support, the latter ordinarily being a heavy stamping or rolled member. Such 'rasp bar may be three feet or Vmore `in lengthand must be very iirmly and `accurately mounted in view oi the vheavy stresses and strains to which it is subjected in use. Spot Welding Ais not practicable due to the thickness-of the two articles to be joined, riveting is not practicable since the exposed face of the rasp lbar is provided -with fairly closely spaced serrations, and the usual arc welding operation would take too long, 'requiring the laying of a substantially continuous bead Zalong both sides of the bar.

It is accordingly a :primary objectof our invention to provide an -arc Welding device and method whereby two metal .members vmay be joined in a local region only to obtain an eect similar to riveting butI without penetrating entirely through one of the members thus joined.

Another object is to-provide such device which will be automatically operative thus to secure together two such members at spaced points along their lengths.

Still another Objectis to provide suchl machine in which the usual automatic -arc `Welding head adapted to feed a continuous length of weldrod to the work may be employed.

Other objects will appear as the description proceeds.

To the accomplishment of the foregoing .and related ends, said invention then comprises the features Ahereinafter fully described and particularly ypointed out in the claims, -the following 2 description and the annexed drawing setting for-th in detail certain illustrative embodiments of the invention, vthese being indicative, however, of but a few of the various ways in which the principle of the invention Imay .be employed.

In said annexed drawing;

Fig. 1 is a 'front elevational view of a dual machine embodying the .principles of :our invention wherein two .sets of work-pieces may be simultaneously operated upon;

Fig. 2 is an end elevational view of .the .mafchine of.Fi-g. l;

.Fig 3 Ais a .front elevational view .of the upper portion of one of the flux return elevators servicing each of the two respective welding heads;

Fig., 4 is la vertical sectional view taken lalone' the line 4 4 on Fig. .1 andshowing the mounting of one of such welding heads and work clamping means *on an enlarged scale;

Fig.. 5l iis a fragmentary iront elevational vView of the tcen-ter Aportion of the .dual .machine of Fig. 1;

Fig. l6 is ahorizontal sectional View taken .along the .line 6--6 on Fig. 4 and showing one .of the welding hea-d supporting carriages.; Y

Fig. y7 is asimilar View takenvalong .the line 'l-lon Fig. 4 `somewhat .higher-.on .the machine;

Fig. 8 is -a .fragmentary top .plan view `of .one of the work clamping devices taken on the line 8-8 on Fig. '4;

Fig. 9 isa .front elevational detail view .of a portion of 4one .o'f the .control bars having vcontrol cams mounted thereon;

Fig. .l0 is a vertical .sectional view taken .along the line lll-lDonFigQ;

Eig. 11 is a detail perspective vview of .one of the cams mounted y on such .control bar;

'.Fig. 12 .is 4a .fragmentary view of a .section of a combine v.rasp bar .illustrative of the 'type .of product which may be fabricated -upon the lmachineof our invention;

Fig. .113.is .an .end elevational view of .such rasp bar.;.and

Fig. 14 is an .electric and iluidpressure `diagram of the control system for ourfnew machine.

Referring now more particularly 'to such ndrawing and especially Figs. .1-4 thereofl the preferred embodiment oi our invention there illustrated-comprises a. mainframe .l fabricated of Welded steel ,plateand supporting end :columns 2 .and .3 adjacent 'theirespective ends "of .'its'lo'wer rear `deck 14. Also .carried vby Lsuch vbase "frame intermediate columns 2 .and 3 are .slightly 'higher columns 5 and 6 which 'have Welded vvthereto three abutting Yhorizontally disposed backing plates J, '8 and .9. "Plates "l yand v'9. are voi the l 3 same length but intermediate plate 8 is consider-ably longer and has a spacer bar lli welded thereto to the face oi which is welded a slightly wider plate iI adapted to serve as a trackway ior a purpose explained below.

The forward' upper'deck i2 oi base liincludes a trough I3 leading to a chute I4, the lower end of which leads to an inclined conveyor trough I of conventional design adapted to be shaked by `iogging mechanism It to cause its contents to travel downwardly into the lower end of elevator I1. Such elevator I1 is also of generally conventional design comprising an endless chain"` provided with scoops adapted to pickup material in the lower end oi the elevator and transport it to a hopper it at the upper end thereof for discharge down flexible hose I9. rEhe elevator chain (not shown) may be driven by pulley 2l on shaft 2Q, powered by motor-driven pulley 2. As indicated in Fig. l, two such trough and elevator systems areprovded in the dual machine there illustrated which is adapted to accommodate-two sets of work-pieces simultane ously, as later explained in more detail.

The work holding means The work, in the example here illustrated, comprises a combine rasp bar 23 having serrations 2t which is to be attached to a channel-Iorm supporting member 25. f Such bar and channel will preferably rst be tack welded together at spaced intervals therealong in order to facilitate handling of the same.

4LA' work-piece holder comprising two spaced bars 26 and 21 extends across the width of the machine above the rear portion of troughs I3. Such bars 26 and 21 are somewhat spacedapart to permit any excess granular nux to drop down into troughs I3. Such troughs may desirably be provided with screens 2S to catch any fragments of coalesced flux which may drop therein. -The upper surfaces of bars 26 and 21 are contoured to conform to the shape of the rasp bar whereby to orient and 'rmly seat the latter in the machine. A plurality of brackets 29 are adjustably mounted along the rear side of upper deck I2 and are provided with bifurcated linger members 30 pivotally mounted thereon. The two spaced finger ends 3 I areturned down to bear against the back of channel member 25 and clamp the same firmly against underlying Vrasp bar 23. Each such clamping iingeris operated by a iiuid pressure piston 32 and cylinder 33 pivotally mounted at 34 on a bar 35 likewise adapted to be adjustably positioned lengthwise of the work supporting fixture. As will be explained below in conjunction with a description of the operation of the machine as a whole, all of the fluid pressure piston-cylinder assemblies for the right-hand 'side of the machine are adapted to operate simultaneously and likewise such uid pressure assemblies on the left-hand side of the machine will operate simultaneously but not necessarily at the same time as those on the right-hand side.'l

yThe arc welding mechanism Two identical arc welding heads are mounted upon individual carriages for independent traverseback and forth above their respective workpieces. Each welding head supporting carriage comprises a at plate 36 (see Figs 6 and 7) having an upper flange member 31 adapted to extend over rail I.I and a lower flange member 38 extending beneath such rail. Two rollers 3S and 40 carried by such upper ange 31 rest upon the top of the rail and support the carriage. Four pair of spaced rollers 4i, 52; 43, 44; 45, 46; and 41, 48 likewise carried by such upper and lowerflanges bear against opposite sides of rail II mounting the carriage for reciprocation therealong. A Vertical slideway 49'is secured to plate 36er each such carriage and carries Ya vertically disposed duid pressure cylinder 50 on its upper extension l 5 I. Piston 52 of such cylinder is secured to slide 53 and is thereby operative to reciprocate such slide up and down on slideway (t9.

A` iordwardly extending arm 5d on such slide j carries a conventional arc welding head 55. Such head is provided with a flux receiving hopper 58 into which the lower end of iiexible hose IS is adaptedto extend, such hopper feeding iiux to the tubular conduit 51 enclosing the continuous bare wire electrode 5B drawn from a reel (not shown). An electric motor 59 on head 55 serves to advance the electrode toward the work.

The traversing mechanism While the rightand left-hand parts cf the machine so far described have been identical (that is to say, mirrow images of one another), the traversing mechanisms for the respective welding heads while identical in detail are, however, oiiset one from the other as best shown in Fig. 1.

The traversing mechanism for the right-hand welding head comprises a fluid pressure cylinder Si! secured at one end to column 3 and at the other end to lower backing plate 9. The piston 6| extending from the right-hand end of such cylinder issecured to depending bracket 6?. mounted on the underside of lower flange member 38 of the welding head carriage. rIhus, when piston Si is extended from cylinder iii?, the right-hand welding head will be moved to the right as viewed in Fig. 1,and such welding head will be returned to the left when such piston is retracted.

A similar traversing mechanism for the left-- hand welding head comprises elongated cylinder 'f 63 secured at its right-hand end to the upper portion of column 2 and at its left-hand end to upper backing plate f5. Piston 6d extending therefrom is attached to upstanding bracket mounted on upper iiange member 31 of the left-hand welding head carriage. Such latter carriage and welding head will therefore be moved to the lett along rail I i when such piston is further extended.

General operation As shown in Figs. a and 8, the work-piece assembly is located in the xture comprising contoured bars 2S and El with the rasp bar proper 3 underneath and the channel 25 on top. Piston-cylinder assemblies 312, 33, are now actuated to rock clamping fingers 3e to bring downturned operator may remove and replace work from one section while the other section is automatically completing its cycle.

vUpon pressing the start button, the welding head is caused automatically to traverse until it is above the irst clamping linger with the end of electrode 5S directed toward the work between Y finger ends 3i. tooperating position and begins to inch the electrode toward the work. When the electrode contacts the work, iiux is discharged from hopper 56 and tube 51, covering the electrode end, and the arc starts. period of time, the arc is shut oli and the welding head raised, whereupon the head now traverses until above the next ngerwhere the above-de scribed cycle is repeated. This sequence of traverses and welding operations continues until a weld has been made between each pair' of clamping .finger ends. The clamps are now raised and the'. operator removes the finished welded article and .again loads the machine. The next sequence of operationis the same as before except that the welding.head will traverse in the opposite direcf tion.

Asrbesti'shown in Figs. 8 and 13, veach weld will comprise ahead or' button 66 of deposited weld metal. and a further narrower portion of melted metal 611extending through channel 25 Vwell into rasp bar 23 but not penetrating to the'underside of the latter. Channel 25 is thus secured to bar 23 by means of a weld which in addition to the usual weld c bond also resembles a rivet v.in mechanicallyholding the two members together.

Excess granulated.L fluxfdrops into trough I3, the operator brushing off the work-holding iixture Ybefore placing new work therein. The screen 28 catches any coalesced fragments of flux. which may not adhere to the work` and the excess rgranulated flux, descends to thelower end of elevator l1, is lifted to the top of the latter, and returned to hopper 56 of the welding head through flexible hose I9. The operator may conveniently replenish the flux supply from time to time simply by depositing additional nux in trough I3.

` Detailed operation Reference may now additionally be had to Fig. 14 of the drawing, in conjunction with Figs.`1, 2 4, 5, and 9 to 11 inclusive, for an understanding of the `manner in which the movements of the welding heads and work clampingmeans `are controlled.

Each welding head is provided with its own control system" since the machine is a dual machine, each side of which may be operated independently of the other. Fig. 14 accordingly diagrammatically illustrates the electrical and fluid pressure system for but one Aof such sides.

The right-hand welding head 55k (as viewed'in Fig. l) is connected by means of depending bracket 62 with the end of piston 6l. Such bracket yis also joined by means of downwardly extending leg 68 and screws 69 to control bar 1U mounted in interrupted slideway 1l for reciproc'ation with and parallel. to piston 6I. A limit switch 12 is mounted on backing plate 9 adjacent the end of cylinder 60 and provided with a down'- wardly extending operating arm 13 adapted to be successively engaged by upper cams 14 mounted at spaced'intervals on control bar 1li. Such cams' are" spaced at intervals corresponding to the spacing of'thework clamping'ngers 3U and serve 15o-operate limit switch 12 to halt the'welding head at each welding station in a manner explained below. Such limit switch is. also operative to close thecircuit controlling lowering of the welding head into welding position at each such station. Below bar is a spring-backed plunger l5 carrying a roller 'I6 at its upperv end' adapted to be engagedl by lower cams 11 on bar 10 to. depress such plunger; The purpose of this plunger is to The welding head nowdes'cends".

After expiration of a predetermined operatemeansfslowingown-tne.transverse move.

ment of the welding-head just beroreftheilatter 1s broughtto a stop by operationv of: switch` 12. This avoids jerky movement of thel-ieadandper mits halting thesame at .precisely the. desire@ point- Bol'fh'types of cams are beveled-on each. side, permitting. the` control mechanism.tofumaV tion inboth directions. Since limit switch 12 `isi above `plunger 15, theupper and lower camsfare disposed in corresponding pairs. .They may be adjustably positionedalongbarT asnecessaryto ensure actuation of the: welding head. atthe proper 'points with regard 'to then-work-clampingi' fingers.

As indicated, the left-bandV welding head jcFg; 1) is similarly controlled, its-controlbar 10' being mounted in slideway 1I' for Ireci-procation parallel to traversing piston 64. Limit' switch 12 is -mounted on backing plate 1 adjacent theendof cylinder 63 and belowbar 1U', its upwardlyexe tending operating *arm 13 'being vadapted to besuccessively engaged by lower cams 14 mounted at spaced intervals on such bar. Above lbar- 10 is a spring-backed plunger 15 carryingearolle'r 16 at its lower end yadapted to be engaged by upper cams 11l on ybar 10 to reciprocate such plunger as such bar is traversed. Thefunction of all such elements is as described Vabove in. connection with the right-hand weldinghea'd.

Referring now more specically to 14 ofthe drawing, the operation of one such welding head will now be described in detail.r The-oper'- ator places the work such Aas barv 23 and channel 25 in the wo'rkholder` comprising fixtures 26 and 21. He then throws main switch`118`, ener?- gizing the electric circuit through control transformer 19 and terminal block 8D, and operates4- Way hand valve 81, admitting fluid pressure to clamping cylinders 33 and causing' iingers 30 firmly to clamp the work. Such actuation 'of cylinders 33 and their pistons 32 causes the lat ter-to engage and operate limit switch 82, completing the Welding head traversingcircuit except for the Forward button. It will-thus be. seen that the welding head cannot normally'be actuated until the work has vbeenV properly' clamped in position.

The operator nowv d'epresses such Forward button, energizing control relay 83which operates solenoid-controlled valve 84 to admit fluid prese sure to the left-hand end of cylinder 60 (Fig. 14) ,Y thereby causing welding head 55 tov begin its traverse. When the first cam 11 engages roller 16 of plunger 1-5, the latter is depressed to close straight-Way valve 85 and thereby throttle down the speed of such traverse since iiuid flow is now bypassed through needle valve 86. Simultane-v ously,y the first cam 14 engages arm 13 of limit switch 12, energizing time delay control relay 81 through the normally closed contacts of re4 lay 88. This energizes relay 88 which closes the conventional arc holding circuit of the welding head and actuates four-way valve 90, admitting iluid pressure to the upper end of cylinderv 50 to lower the weldinghead into welding position.

When' the welding head reacheswelding posirr tion, limit switch 9| is operated thereby. 'energizing control relay 92, closing the electrode wire feed motor armature' circuit and wire inching circuitV (conventional ini automatic arc-welding heads) and thereby' causing the wire electrode to' be moved toward the work and contact the same; between the spaced nger ends 3| of clamping member 30. When the wire thus contacts the s work, the welding circuitis closed, actuating cime trol relay 93 which energizes flux valve solenoid 9B to cause flux to be delivered from hopper 56 down tube 57 about the electrode and upon the,

work. Actuation of relay 93 alsoserves to energize time delay control relay 95 which in turnenergizes relay starting the arc. complishes this result by closing the'i'leld circuit of the conventional welding generator and thereby causing a weldingl current to besent through theA previously closed welding circuit. When the arc is started relaysSl and S8 are energized, relay 97 de-energizing relayf., When the allotted welding time has elapsed, time-delay relay 98 de-energizes relay S2 and energizes relay ill2 which energizes control relay 83. Relay 38 in turn de-energizes relay 89, thereby de-energizing the arc-holding circuit, shutting oli the are, reversing valve Si) to elevate the welding head, and again operating valve $55 to admit iuid pressure to cylinderll to resume the traverse or the head. While time-delay relay Si is of course again actuated when the welding head rises to its upper position, the head traverses away from the actuating cam before such time delay period runs out so the head will not be reciprocated downwardly until the next cams reach operative position. The next set of cams thereupon become effective to repeat the welding cycle when the welding head attains a position above the next work-holding clamp. Y

It will, of course, be understood that the welding head above described is not of our invention but is the well-known and commercially available Lincoln automatic arc-welding head. No

detailed explanation of its construction and operation is accordingly required, since it is well known to those skilled in the art. The manner of traversing and reciprocating the same, and the welding operation performed, are however believed to be novel and to produce much improved results.

When the welding head has completed the full traverse, limit switch 99 is engaged, dropping out control relay S3 and shutting oil the complete control circuit. The operator thereupon again operates hand valve 3| to open the clamps and removes the welded work-piece. After loading the machine and closing the clamps, he now presses the start Reverse button, energizing control relay lili] and the sequence ofoperation above described is repeated, but with the traverse in the reverse direction since valve 84 is shifted to apply uid pressure to the rod end of cylinder 60. Upon completion of the entire traverse in this direction, limit switch ll is engaged, dropping out control relay lill) and shutting ori the control circuit. The operator unelamps and unloads the work, and the machine is again ready for reloading and forward operation. Y

It will thus be seen that we have provided novel welding mechanism adapted automatically to weld two members together at spaced points therealong. We obtain the advantages of arcwelding, spot-welding, and riveting in a single operation, obtaining a localized weld which need not penetrate entirely through both such members. The resultant assembly is extremely strong and rigid and capable of withstanding very severe usage. The electrode is not ordinarily traversed during` the actual welding operation, a rivet-like weld being produced having a button or head on the upper surface. It is, however, possible to traverse the electrode during the welding operation, if desired,to produce an elon- Relay 96 ac-` gated weld of this type. A bare wire electrode is ordinarily employed and a relatively high current density, up to '750 and even 1000 amperes with one-eighth inch diameter electrodes is utllized. 1 I

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We therefore particularly point out and distinctly claim as our invention:

l. In welding apparatus for arc-Welding two elongated metal members together in spaced local regions along their length, supporting means adapted to support such members in juxtaposed position in a horizontal plane, a series of pairs of pivotally mounted spaced clamping fingers adapted to clamp such members together on said supporting means, fluid pressure piston-cylinder assemblies operative to rock said pairs of fingers thus to clamp and unclamp the work, an automatic arc-welding head mounted for horizontal traverse above and parallel to such work, a fluid pressure piston-cylinder assembly operative thus to reciprocate said head, a vertically disposed piston-cylinder assembly supporting said head and adapted to traverse therewith, said latter assembly being operative to lower and raise said head into and out of welding position relative to such work, control means adapted automatically to stop such traverse of said head above said pair of clamping ngers in sequence, with the welding electrode of said head directed toward the region of such work therebetween, and control means thereupon operative to actuate said vertically disposed pistoncylinder assembly to lower said head into welding position, and to raise said head out of welding position upon expiration of a predetermined welding time interval.

2. In welding apparatus for arc-welding two elongated members such as a combine rasp bar and a channelform support together in spaced local regions along their length, a jig adapted to support such bar in horizontal position with such channel resting thereon, a series of pairs of pivotally mounted downturned clamping lingers at spaced intervals therealong adapted to clamp such members together on said jig, fluid pressure piston-cylinder assemblies operative to rock said pairs of fingers thus to clamp and unclamp such work, a trackway parallel to said jig and such work, a carriage mounted for reciprocation along said trackway, a vertically disposed slideway on said carriage, an automatic arc welding head mounted for vertical reciprocation along said slideway above such work, a uid pressure piston-cylinder assembly operative thus vertically to reciprocate said head into and out of welding position, a fluid pressure piston-cylinder assembly operative to reciprocate said carriage, control means adapted automatically to stop such traverse of said carriage with said head above each said pair of clamping fingers in sequence, with the welding electrode of said head directed toward the region therebetween, control means thereupon operative to actuate said piston-cylinder assembly operative to lower said head into welding position, and to raise said head out of welding position upon expiration of a predetermined welding time interval, a flux elevator, a flexible hose leading from the upper end of said elevator adapted to deliver flux therefrom to said s welding head. a trough beneathsaid jigadapted to.: receive surplus iiux, and means adapted to deliverfiux from'said trough to the lower end of `said elevator.

.operative thus to traverse said arc-welding head,

means operative vertically to reciprocate said arc-welding head to lower and raise the same into and out ci welding position relative to such work, a control bar connected to said arc-welding head fior horizontal travel therewith, said control'bar extending parallel to such horizontal path of travel, electric control means adapted to energize such means for vertical reciprocation of said arc-welding head and including a switch operative when actuated to energize said electric control means, and a plurality of switch actuating members secured in longitudinally spaced relation on said control bar adapted sequentially to traverse parallel to such work and for reciprocation toward and away from such work, drive means operative thus to reciprocate said arcwelding head along such path of horizontal traverse, drive means operative to reciprocate said head toward and away from such work into and out of Welding position, control means automatically operative to halt such horizontal traverse at predetermined locations, and control means automatically operative to actuate said second drive means to reciprocate said head toward said work for initiation of a welding operation and to withdraw said head out of welding position after elapse of a predetermined welding interval and prior to further traverse of said head.

5. In welding apparatus for arc-welding metal members together in spaced local regions, clamping means operative firmly to clamp such members together, an arc-welding head mounted for traverse parallel to such work and for reciprocation toward and away from such work, drive means operative thus to reciprocate said arcwelding head along such path of horizontal traverse, drive means operative to reciprocate said head toward and away from such work into and out of welding position, control means automatically operative to halt such horizontal traverse at predetermined locations, and control means automatically operative to actuate said second drive means to reciprocate said head toward said work for initiation of a welding operation and to withdraw said head out welding position after elapse of a predetermined welding interval.

6. In welding apparatus for arc-welding metal members together in spaced local regions, clamping means operative rmly to clamp such members together, an arc-welding head mounted for traverse parallel to such work and for reciprocation toward and away from such work, drive means operative thus to reciprocate said arcwelding head along such path of horizontal traverse, drive means operative to reciprocate said head toward and away from such work into and out of welding position, and control means automatically operative to actuate said second drive ,means'to reciprocate said head toward said work for initiation of a welding operation and to withdraw -said head out of welding position after .elapse of a predetermined welding interval.

7. In Welding apparatus for arc-welding metal members together in spaced Alocal regions, clamping means operative ilrmly to clamp suchmemybers together, an arc-welding head mounted for ,traverse parallell to -such work and for reciprocation toward and away from such work, drive means operative thus to reciprocate said arcwelding head along such path of horizontal trav;-

erse, drive means operative to reciprocate said head toward and away from such Work into and out of welding position, a control bar mounted for travel with said -head jon such horizontal traverse, said bar extending parallel to the rpath .ci such traverse, aplurality ofcontrol-actuating members pny said bar at 'spaced intervals therealong, and controlv meansrposit-ioned forv repeated actuation by said control-actuating members duringftraverse and to energize said drive means operative.y to reciprocate said headl towardl and away from such work. f

8. In welding apparatus for arc-welding metal members together in spaced local regions, clamping means operative rmly to clamp such members together, an arc-welding head mounted for traverse parallel to such work and for reciprocation toward and away from such work, drive means operative thus to reciprocate said arcwelding head along such path of horizontal traverse, drive means operative to reciprocate said head toward and away from such work into and out of welding position, means automatically operative to halt such traverse of said head at a plurality of predetermined stations, and means automatically operative to energize said drive means to reciprocate said head toward and away from such work into and out of welding position during the period of each such halt, said head being operative to make a Weld when in stationary position adjacent such work at predetermined length of time, and said head being capable of further traverse only after interruption oi' each such local welding operation.

9. In welding apparatus for arc-welding metal members together in local regions, supporting means adapted to support such members in superimposed position thereon; clamping means comprising a pair of spaced clamping fingers pivotally mounted to rock into and out of clamping engagement with such Work to clamp the latter rrnly together against said supporting means, a fluid pressure piston-cyclinder assembly operative thus to rock said fingers; an automatic arc-welding head mounted for reciprocation toward and away from one of such members into and out of welding position with regard thereto in the local region between said ngers, said lingers being spaced to lie closely to either side of the weld thereby produced; and means adapted to restrain said head against movement during the welding operation.

l0. In welding apparatus for arc-welding metal members together in local regions spaced from the edges thereof, spaced clamping lingers operative to engage one such member to force such members together against a support; an automatic arc-Welding head mounted for reciprocation toward and away from the local region of such member lying between said lingers, thus moving into and out of welding position, said ngers being spaced to lie closely to either side of the weld thereby produced; and means adapted to restrain said head against lateral movement during the welding operation.

11. In Welding apparatus for are-welding metal members together in spaced local regions, clamping means operative rmly to clamp such members together, an arc-welding head mounted for traverse parallel to such work and for reciprocation toward and away from such work, drive means operative thus to reciprocate said arcwelding head along such path of horizontal traverse, drive means operative to reciprocate said head toward and away from such work into and out of Welding position, a control bar mounted for travel with said head on such horizontal traverse, said bar extending parallel to the path of such traverse, a plurality of cams on said bar at spaced intervals therealong, an electric control system including a switch adapted to be engaged and operated by said cams, said control system thereupon being operative to stop said means to reciprocate said head away `from such work, de-energize such electrode feed motor. and re-energize said head traverse drive means to resume traverse of said head until the next said cam engages said switch.

CECIL C. PECK.

WILLARD GUNZELMAN.

REFERENCES CITED The following references are of record in the file of this patent:

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